Radioreceiver



Oct. 22, 1935. J N N 2,018,081

RADIORECEIVER Filed NOV. 16, 1931 5 Sheets-Shet 1 Bk INTON.

Er BY v I ATTORNEY Oct. 22, 1935. J. P. MINTON 2,018,031

- RADIOREECEIVER Filed Nov. 16, 1931 5 Sheets-Sheet 2 INVENTOR ATTORNEY IPMINTON.

J. P. MINTON RADIORECEIVER Oct. 22, 1935.

Filed Nov. 16, 1931 3 Sheets-Sheet 5 INVENTOR 15b PM INTO/V.

Q 4 QM ATTORNEY Patented Oct. 22, 1935 UNITED STATES FFICE mesne assignments, to

said Minton and Herbert H. Frost, New York, N. Y.

Application November 16, 1931, Serial No. 575,176

10 Claims.

This invention relates to improvements in radio receivers, and particularly to radio receivers of portable design and reduced size.

An object of the invention is to provide a radio receiver in the form of a compact, handy and complete unit; with all the necessary parts thereof, including a loud speaker, mounted upon a chassis, common support or base; the parts being conveniently arranged on the base and firmly secured in position, so that the entire construction can be housed in a casing or cabinet by handling it as a whole to put it into the casing; and just as easily remove it therefrom.

A further object of the invention is to provide a radio receiver of small compass with all the necessary parts thereof mounted upon a base or framework that is strong and rigid in construction, but exceedingly light and easy to make in the form required, to carry all of the parts and to mount the loud speaker in central or other desired position. I

In its preferred form the receiver has connections and appliances tov enable it to be energized from a light or power circuit of a building; therefore batteries are not required and the framework therefore bears not only the tubes,

coils, condensers, loud speaker and other necessary elements, but also all the necessary means for converting power or lighting current into such form so that it can be advantageously used to energize vacuum tubes and the coils of the loud speaker.

Other objectsand advantages of the invention are set forth in the ensuing description, taken with the accompanying drawings, which disclose a preferred embodiment of the invention. I do not, however, wish to limit myself to the exact structure herein set forth, but reserve the right to make changes in various'ways to the full extent which is consistent with the breadth of the terms in which the appended claims are expressed and does not exceed the scope thereof.

On the drawings:

Fig. 1 is a front View of a radio receiving set showing the support for the various parts in a suitable casing, the latter being shown in Vertical section;

Fig. 2 is a top plan of the radio receiver with the casing shown in horizontal section; and

Fig. 3 is a transverse section on the line 3-3 of Fig. 1.

On the drawings the same numerals identify the same parts throughout.

To support the loud speaker, tubes, and other members of the apparatus, I provide a framework or chassis I of sheet metal in the form of a table or platform having a flat top, and the front and rear edges bent downward at 2 to stiffen and reenforce the top. At the ends are legs 3 which form part of the chassis and enable it to be stood 5 upon any suitable supporting surface. Most of the parts of the radio set are mounted on the upper surface on the fiat top of the base I butsome are disposed beneath it and the loud speaker is preferably in central position adjacent a suit- 10 able opening in the front of the casing or cabinet for the set.

At one end of the base or chassis and on the top thereof are variable condensers 4 to tune the various stages; the movable elements of these 15 condensers being all attached to a common shaft 5 that projects through an opening in the front of the casing to receive a suitable operating knob. Hence by turning the knob, the shaft 5 is operated to adjustallof the condensers together. I 20 have illustrated three condensers, one behind the other from front to back of the apparatus and three tubes 6, one of which may be an audio frequency amplifier, similarly arranged on top of the support I besides the condenser l. Adjacent 25 the other end of the chassis is the detector tube '5 and besides this tube is a rectifier tube 8. Both tubes 1 and 8 may be located towards the rear. In front of these tubes are a transformer 9 and a container It for electrical condensers. The 30 transformer 9 and the condensers in the container it] are adapted to cooperate with the rectifier tube 8 to convert, alternating current into smoothed-out direct current for the anodes of the tubes and to energize the cathodes thereof, or the 35 cathodes may be heated by alternating current if desired.

Adjacent the middle of the chassis there is a recess II in the top thereof to make room for the loud speaker indicated at I2. This loud 9 speaker comprises a vibrating diaphragm, the outer edge of which in combination with suitable packing I3 is secured between two rings I 4, held fast to each other by screws or other securing means. Two of these screws indicated, for example, at i 5, afiix the rings M to the front flange of the this front flange being cut away in the middle as indicated at I6 '00 make clearance along with the recess I l for the loud speaker I2. 50 When the chassis bearing the various necessary parts of the receiver is inserted into the casing or cabinet ll, the loud speaker will be disposed in registry with a central opening H3 in the front of the cabinet so that sounds reproduced by the loud speaker can be transmitted without obstruction.

Preferably the cabinet I? is closed at its sides, top, bottom and front, but open in back; so that the chassis i with the various parts thereon can be put into the receiver or taken out and the 7 back of the receiver can be closed with a removcircuit' of the detector T.

7 set, thisbox having flanges for fastening screws.

Adjacent the container 22 and below the top of the chassis, i is also placed the iron core 23 of a transformer coil 24 which is to be in the output This iron core 23 is afiixed to the lower end of a vertical bridge or yokeplate 25; having its ends bent to engage the rear ring M of the loud speaker and attached thereto in'any suitable way and with its middle portion adjacent the rear of the conical diaphragm of the receiver 12, and with an opening therein for the connections between the dia-- phragm' and the actuating armature. Just behind this bridge or yoke plate 25 is a magnetic yokeZS anchored by means of bolts 2? to a plate 28 abutting and secured to the yoke 25. Within H the yoke 26 are the operating coils of the loud speaker shown at 29, and to the rear of this member 25 is an angle-plate 30 secured to the member and to the chassis 2 to anchor the member 26- --with the magnetic coils 29 therein. 7 The angle plate'3il alsocarries a ground terminal clip 3|.

Adjacent the upper part of the bridge plate 25 is mounted the antenna condenser 32 which can be adjusted by the knob 33. To one side of the loud speaker is the switch 34 combined with the volume control device which is manipulated by means of a shaft 35 extending through an opening 31 in the casing H. and provided with a knob not shown at its outer end. A fixed plate 38 is secured to the chassis in front of the 'volume'control device 35 and this plate carries at'the upper end a bracket 39 to support the switch 34.

Rising from the end of the chassis adjacent the condensers 4 is a plate 40 affixed to the i chassis.

and connected to vertical transverse plates 4! which serve as partitions or shields betweeniadjacent condensers 4 and provide compartments for each of the condensers. The end walls 42 for the front and rear condenserscarry bearings for the shaft 5, and at 4-3 are connecting bars diagrammatically shown for the movable plates of the condensers. On the shaft 5 is a transparent dial M the face of which is marked with angular degrees of rotation 45 to indicate the position of adjustment of the condensers and these marks may sh'ow through a peep hole. not

illustrated, in the front wall of the cabinet I l.

V At' lii is a lamp to illuminate this dial which may be of'transparent or translucent material.

.I also provideshields 41 between the vacuum tubes 6, these shields being in. the form of metallic plates which are made fast to the plates 4| and 75 extend vertically upward from the chassis, with a common hood or cap 48 engaging these shield 3" plates 41 at the top.

In other words when the speaker is rigidly and directly connected with the chassis, which has considerable mass and all of its members rigid with one another, and when the speaker is not secured to the cabinet or casing 11, any vibrations of the diaphragm which might otherwise disturb the tubes are suppressed by the chassis. On the other hand if the speaker l2 were not rigidly and directly connected to the chassis, then the vibrations of the diaphragm would cause 10' other vibrations in the set which would be transmitted through the various parts, and disturb ance of the tubes above described would result.

The conducting cord for connecting the set to a power circuit or wall socket is indicated at 49 15 and the antenna lead wire is shown at 5t. Both of these leads pass out through suitable openings in the rear 59.

At beneath the chassis i and attached there- .to are hoods or chambers for the coils of the .cir- 0 cults associated with the condensers and tubes.

52 indicates an opening in the top I for the transformer 9.

The 1egs3 of the chassis may be in the form of plates at the ends of the top I with side flanges 25 53 and bottom flanges 54 to reenforce and strengthen these plates and make them stiff enough to carry the weight of the set. V

The entire construction and arrangement of the parts of the receiver are thus quite advanta 30 goons; and while the receiver is very compact, nevertheless all of the parts thereof are rendered very accessible for inspection, examination or re pair. The various parts are held fast to the chassis by means of screws or the likeand can 5 be taken off whenever necessary. The mere re moval of the closure l9 permits the extraction of the entire radio from the cabinet and then any tube, coil, condenser or connection'thereto,

can be given whatever attention is needed. Pref- 40 L erably the various conductors are mostly be"- neath the top of the chassis, although some may be above. it and the set, always presents a neat, ready and orderly appearance. As thus made up the set is unitary and complete and the loud 45' speaker is incorporated therewith instead of be-. Q ing separate and required to be connected by an outside cable. r

l-Iaving described my-invention, what I claim l. A radio receiver comprising a sheet metal chassis having a flat top and flanged along its front and rear edges, said'chassis' having an inward extending recess in its top and front flange,

a loud speaker projecting into said recess and 55 having its front substantially flush with the front of said chassis, and retaining rings at the front of the loud speaker affixed to the front flange at V the of said recess.

2. A radio receiving set comprising a. sheet 60.

metal chassis having a flat top. with flanged edges at the front and back and legs at the sides, the legs being attached to said flanged edges,

tubes and condensers mounted on the upper sur face of the chassis, a condenser casing and transformer below said top, the top also having'an' f opening and a second transformer coil disposed i in said opening, and a centrally located loud speaker at the front of the chassis and 'SfilXGd'Td thereon. 3. Airadio receiver comprising a chassis of sheet metal having aflat top with flanged front and rear edges and legs at the ends, said chassis; having a' central recess-in its top adjacent the front, a loud speaker, means'to hold the loud speaker in the recess with its front substantially flush with the front of the chassis, and having at one side of the recess an opening for the coil of a transformer, the sides of said speaker beingaffixed to the flanged front edge of the top at the sides of the recess.

l. A radio receiver comprising a'chassis having a flat top with a recess therein at the front, a loud speaker projecting into said recess and substantially flush with the front of the chassis, a vertical bridge plate attached to the loud speaker at its top and bottom and projecting into said recess, a magnetic yoke secured to the rear of said bridge plate, coils in said yoke for said speaker, and means for attaching said yoke to the chassis.

5. A radio receiver comprising a chassis with a flat top having a recess in front adjacent the center thereof, a loud speaker mounted on the top or the chassis and projecting into the recess and secured with its front substantially flush with the front of the chassis, a bridge plate rigid with the center of the chassis and attached to the rear of the loud speaker at the top andbottom thereof, and a variable antenna condenser mounted on said bridge plate.

6. A radio receiver comprising a chassis with a fiat top having a central opening at its front, a loud speaker and a bridge plate projecting into said opening and holding the loud speaker in the recess with its front substantially flush with the front of the chassis and a transformer supported by the bridge plate below the top of the chassis, said bridge plate being secured to the inner end of said recess.

7. A radio receiver comprising a chassis with a flat top having its front and rear edges flanged and with legs at its ends, the front of the top being centrally recessed, a yoke aflixed to the top at the inner end of the recess, a loud speaker at the open end ofthe recess and having its front substantially flush with the front of the chassis, a coil in said yoke in the rear of said recess to operate the loud speaker, a bridge plate secured to the top and bottom of the loud speaker and projecting into the recess, a plate aflixed to the rear of the bridge plate and anchor bolts to secure the yoke and plate together.

8. A radio receiver comprising a chassis having a flat top, a loud speaker centrally mounted on the top of the chassis, the top of the chassis having a recess receiving a loud speaker, the front of the speaker being substantially flush with the front of the chassis and being secured to the top at the sides of the recess, means forming condenser compartments on said top at one side of the loud speaker, vacuum tubes on said top besides said condensers, vertical plates between said tubes, and a cap plate supported by said plates between said tubes.

'9. A radio receiving set comprising a chassis supporting the various parts of the set thereon, the chassis being of reenforced sheet metal having a flat top and supporting legs, the parts on said chassis comprising a loud speaker, the chassis having a recess in which the speaker is disposed with its front substantially flush with the front of the chassis and secured to the top at the sides of the recess, a; casing having a closed front, bottom, top and ends with an opening in front to register with the loud speaker when the chassis is inserted into the casing and a removable closure plate for the rear of the casing.

10. A radio receiving set comprising a chassis, a condenser having a metallic enclosure on said chassis, a loud speaker on said chassis, amplifier tubes between the speaker and the condenser and shielded on one side by the enclosure for the condenser and on the other by the parts of the loud speaker, said tubes also having shielding means over them and between them.

JOHN P. MINTON. 

